Al-'Ankabut 29:3

Walaqad fatanna allatheena minqablihim falayaAAlamanna Allahu allatheena sadaqoowalayaAAlamanna alkathibeen

But We have certainly tried those before them, and Allāh will surely make evident those who are truthful, and He will surely make evident the liars.

Indeed We have tested those who were before them. So Allah will surely know the ones who are truthful, and He will surely know the liars.